Tool grinding machine and the like



July 8, 1947. I J. v. NELSON 2,423,790

TOOL GRINDING MACHINE AND THE LIKE Filed March 29, 1945 8 sheets-sheet 1 INVENTOR. John V Nelson,

July 8, 1947.

J. V. NELSON TOOL GRINDING MACHINE AND THE LIKE Filed March 29, 1945 8 Sheets-Sheet 2 Q Y EL INVENTOR. BY IohnV also.

July 8, 1947. J. v. NELSON TOOL GRINDING MACHINE AND THE LIKE 8 Sheets-Sheek 3 Filed March 29, 1945 INVENTOR. 36hr: V N elson,

July 8, 1947 J. v. NELSON TOL GRINDING MACHINE AND THE LIKE 8 Sheets-Sheet 4 Filed March 29, 1945 v INVENTOR.

John \A Nelson,

u y 1947- J. V. NELSON TOOL GRINDING MACHINE AND THE LIKE 8 Sheets-Sheet 5 Filed March 29, 1945 INVENTOR. 36hr! Nelson,

i l q- I i 1L E i:

y 1947- J. v. NELSON 2,423,790

I TOOL GRINDING MACHINE AND THE LIKE Filed March 29, 1945 8 Sheets-Sheet 6 I N VEN TOR.

, John \ZNelson, I l2.

July 8, 1947. J. v. NELSON TOOL GRINDING MACHINE AND THE LIKE Filed March 29, 1945 8 Sheets-Sheet 7 INVEN'TOR. hnV Ngison,

July 8, 1947. J. v. NELSON TOOL GRINDING MACHINE AND THE LIKE- Filed March 29, 1945 8 Sheets-Sheet 8 Mo. G 8. 9 oh W 0Q. mw

- INVENTOR. Jbhn Nekson,

Patented July 8, 1947 TOOL GRINDING MACHINE AND THE LIKE John V. Nelson, Elmhurst, 111., assignor to Franz K. Krag, Chicago, Ill.

Application March 29, 1945, Serial No. 585,479

4 Claims.

This invention has to do with tool grinding machines, and the like. Generally speaking, the present tool grinder is intended for use in the grinding of cutting tools, that is, tools having lateral or side cutting edges as distinguished from drilling tools, but other uses of the invention will suggest themselves to the student of this application. Furthermore, the present invention is especially intended for the grinding of tools having spiral flutes at or adjacent to the cutting edges, tools of this type being well known and widely used in the machine tool arts.

One feature of the invention is to make pro- Vision for ensuring correct and accurately controlled relation between the grinding wheel and the tool itself during the grinding operations; and in this connection to make provision for moving the tool in proper fashion with respect to the position and grinding position of the grinding wheel, at all times during movement Of the tool itself with respect to the grinding wheel, or vice versa. In other words, to make provision for ensuring correct relation between the tool and the grinding wheel, and to ensure that such correctness of relation will be maintained as the tool and the grinding wheel are moved with respect to each other to bring successive portions of the tool into grinding relation to the grinding wheel.

A principal object of the present invention is to provide a form and arrangement of grinding tool which is very convenient for manual operation, and with the hand or manually operated crank by which the tool holding chuck is rotated placed directly in line with said chuck and directly operating on said chuck, so that a most direct chuck operation is secured, and one whereby a most accurate control of the grinding operation is made possible.

A further object and feature, in connection with the foregoing is to make provision for adjustment of the pitch of movement of the tool carrying chuck during the rotary movement thereof under action of such hand crank, to thereby make possible the grinding of flutes of a wide range of pitches; to make provision for the grinding of each of a plurality of flutes, all of the same pitch, and equally spaced around the periphery of the tool being treated; and to provide a very simple construction, and one which is well adapted to meet practical operating conditions as said conditions are found in the shops where such tools are used. a

It is here pointed out that in order to secure longitudinal movement of the tool carrying chuck at the same time that said chuck is rotated, there is provided a suitable inter-connection between the chuck rotating and the chuck traversing devices; and also, in order to vary the pitch of the flute being ground, or to make it possible to grind flutes of different pitches, means are provided for varying the ratio between rate of angular rotation of the chuckand rate of traverse of said chuck; or for varying the inverse of said ratio. When said ratio is large, that is, when the pitch of the flutes is steep, it will be seen that a large amount of traverse endwise must occur for each rotation of the chuck; and when the force for operation of the device is provided by rotation of the chuck by means of a hand crank it is seen that When said crank is subjected solely to a rotary force, so that the traversing force applied to the chuck is derived solely through the inter-connection above referred between the chuck rotating and chuck traversing devices, there is a limit to the steepness of the flutes which can be ground, depending among other things on the coeflicient of friction of the operating parts, the pressure of the grinding wheel against the flute surfaces, and other factors of the device.

It is a further object of my present invention, by placing the hand crank directly in line with the chuck traverse, and with a direct connection to the chuck rotating connection, to make it p0 sible to subject said crank to either a rotary or a pressure or pull (in the direction of chuck traverse) force, or both such forces simultaneously, so that the necessary traversing and rotary movements may be secured in all cases; sometimes by a simple rotary force, sometimes by a simple push or pull force, and sometimes by a combination of these two forces. Such latter operation will generally be found the most desirable, the operator grasping the crank handle and rotating it in the proper direction, or first in one direction and then in the other direction, and at the same time moving the handle away or pulling it towards himself, as seems necessary and according to the resistance being encountered, and according to the pitch of the flute being treated.

Other objects and uses of the invention will appear from a detailed description of the same, which consists in the features of construction and combinations of parts hereinafter described and claimed.

In the drawings:

Figure 1 shows a plan view of a machine embodying the features of the present invention;

Figure 2 shows a right-hand side elevation corresponding to Figure 1;

follower block; Figure 6 is alsoa View 'takenonthe lines -45 of Figures 2, "3, 4, '5, 'Z and looking in the directions of the arrows;

Figure 7 shows a cross-section on'-'-the lines 1-1 of Figures 1, 2, 3, 6, 8, .9, IO-and '12,.looking in the directions of the arrows; and this figure shows the cam follower block which engages both the rotary table element and the translatory table which carries the tool chuck Figure S-shows a plan "view of thestand'proper, with the'ftranslatory table and other-parts removed;v and is a view taken on the lines-88 of Figures :2,;3,:4,5, 7 and 12, lookinginthe directions of thearrows;

=Figure-9,=shows a view similarwtov that of Figure: 8, "but at a higher elevationxbei'ng taken, on the iine's; 9+9 of Figures 2, 3, 4-,, 5, "7 and 12, lool ing'inthedirections ofthe arrows;

"Figure "l0--shows: a 'top face view of the rotary table, with the cam follower block in place thereon;

Figure 1 1 shows'abottom face view of "the'cam follower bloc-k removed from the rotary table, and hit shows= the bottom of. the rack bar :proper and. the cam follower; element turned tOlan angle corresponding to the :angular setting "20f the turntable 'or. rotary table as 'shown'fin Figure 10;

Figure 12. shows -a longitudinal section taken onfthe lines l2l:2 of :Figures 1,4, *5, 6, "'7, 8, '9 and. '10; looking *in the. directions of the arrows; the translatory table being in the central .--por tion of its translatory travel;

Figure :13. shows a view of a cutting tool of one type 'fo'r which the present machine is adapted;

Figure 14 shows an :end view corresponding toir'igureilis;

Figure 15 shows -a face view of the 'fornrof grinding wheel which is also shown in Figure 1-7 hereoff and 'whic'h form of grinding wheel is adapted "for use inconnection with the present grinding machine ure- Zl6 s'how's. a detail section of the setting pin andra'rm; :beingL'a section taken on the' lines l6-|fiof:Flgures lz'and =6,IloolL'ng in the directions 'of the arr'ows; and

Figure 175 is :a cross-section through the form ofgrinding wheel shown in Figure 15; *and Figure L'Zmay also lee-considered in connection with Figure 12 toshow the relative positions of the grinding wheel and the tool during th grinding operation.

Referring firstto Figures 1, 2, 3, 4 and 5, and others, the machine herein disclosed is convenie'ritly carried by a'base plate or block 29, which is, for :convenience in construction, shown as carrying thestand portion 2|. Sometimes this stand portion may be formed integrally with the base plate, as will be readily'evident from further 'stu'dyof the presentdisclosures. For s'implicit'y said base plate includes the -circularfor ring shaped "flange 22 whichr'rec'eives the forward and rear legs 23 and 24'whi'ch' depen'd from the 4 stand portion proper, and which carry said stand. Conveniently the base plate and the stand are provided with the central openings 25 and 26 respectively. The stand also has the upper portion 2'! extending between the legs 23 and 24, which upper portion is recessed as shown at 28 to receive the circular table 29. The top face of this circular table is registered with the top face of the stand as clearly evident from Fig ures 7 and 1-2, so that both these surfaces lie in a common plane.

The top face of this table 29 is provided with the transverse-channel 3t, constituting a cam within which a suitable cam-follower is adaptedto itravel laterally of the table. The circular table is itself rotatable into any angular set position, so. that the. angle which the channel or cam '3ll will then occupy with respect to the longitudinal axis of the stand can thus be varied into any selected and set angle.

Means are provided for conveniently turning the circular table into any selected positioncf setting, to thereby adjust and set the angle which the transverse cam channel 39 occupies with respect to the longitudinal axis-of the machine. Evidently the 'translatory movement of a cannfollower travellin in said cam channel will'depend on'this angle-of setting oft-he table, so that-by adjusting the angle or set turned position of the table the amount of translation which will be effected =by-the cam-follower may be adjusted into anyzsetramount. -In otherwords, by this vsettin'g'ol thetabl'e into a selected rotary position, the ratio between. lateral and translatory movements effected by a cam-follower travelling :in the cam'channel can be adjusted intoanygiven setting. This ratio between lateral and 'transla'tory movements will in turn 'determine'theipitch or length. of pitcho'f the grind ing operation,:thus :making (possible :correct calibration 'of the machine itself to effect correct grinding of "flutes of different pitches and lengths of pitch. This will presently appear hereinafter.

To turn the-turntable?!) into selected position, and to indi'cate the position into whichit is thus turned, I -have :provided the wheelior circular indicator '3 'connect'ed'to said turntable 2 9. This wheelds conveniently provided with-the upwardly extending-stem :32 which is journall'ed in a verticalbearing 'of t'he tableportion 21. The upper end'of this stem is connected to the turntable 29' so that these'elements retain fixed relationship. Z'Ihis wheel "3 l reaches between the legs 23 and 24', and its edge portion is visible between said legssas shown in' Figures'Z and'3. Said edge is then provided with the calibration readings -33, preferably in the form of degrees orelse in 'readingsof pitch; or the like, which readings are comparable to themar-k Mon thestationary portion 27 Toturnthe-wheel accurately, "and to facilitate close calibration thereof during such'turning, I have shown *the holes spaced around the fla ge of the wheel, and into which a suitable instrument, such as 'a pin, may be inserted to rotate the wheel to a new and selected position. Comparison'of t-he calibration marking .33 with the fixed marked-will at at times inform the operator as to the rotary setting of the turntable, and th-erefore -thesetting of'thecam channel'with respect to "the longitudinal axis of the machine.

To enable locking of the turntable in'anyg'iven set position *1 have provided the set screw 36 which ext'ends fthI'Ollgh the portion 2 1 radially with respect to the turhtable, and the inner end of this set screw may bear against the brake block 31 (see Fig. 9) whichis'set into a suitable recess of the portion 21 in position to be locked against the stem 32 of the wheel, and. thus to lock said wheel in'its set position. Upon setting the turntable into aselected calibration position it may thus be locked during the grinding operation for which such setting has been made.

Carried by the stand, or by the upper portion 21 thereof, there is a tnanslato-ry table 38 which in turn carries the tool chuck. This translatory table 38 conveniently comprises the flat portion 39 which rides on the surface-of the stand portion '21, and which translatory table is provided withthe edge bars 40 and 4| which engage the edge portions of the stand portion 21, and retain the translatory table thereon, while permitting free translatory movement of such table. To this end the edges of the stand portion are chamfered as well shown in Figure '7, and the bars 40 and. 4| are correspondingly bevelled. Said bars are readily removably attached to the under face of the translatory table, as by the screws 42 or similar devices. I g

The bottom face of this translatory table is provided with the transversely extending channel 43 which receives the cam-follower or Ian element connected thereto. By this means proper interengagement is established between the translatory and rotary tables to effect translatory movementof that table in properly calibrated manner as determined at any given time by the rotary setting of the rotary table.

The cam follower is shown in detail in Figures 9, and 11. It includes a, rack bar portion 44 which travels in the channel 43 of the translatory table, which rack bar portion has on its top face the rack teeth 45, and to its bottom face there is pivotally connected the cam block 46 which travels in the cam channel 30 of the rotary table 29. Such pivotal connection is conveniently established by the stud 41 carried by the small plate 48 set into a recess on the bottom face of the rack bar portion 44 and secured therein in suitable manner, as by screws (not shown). It will be seen that when the translatory table is set into position above the rotary table, with the 'cam follower element properly engaged with both the transverse channel 43 of the translatory table and the channel 3|] of the rotary table, there is effected an inter-connection between the translatory and rotary tables which will ensure a relative inter-movement of said parts, depending on the angle of setting of the rotary table at such time. Evidently when the cam channel 30 lies directly across the machine, that is, at right angles to the direction of translation, full back and forth movement of the cam follower can be effected without any motion of translation of the translatory table occurring; and conversely, when the cam channel 30 lies parallel to the direction of translation, full translation lengthwise of the machine may occur without any transverse movement occurring. Between these two extremes various combinations may be secured to \an infinite number. Furthermore, it will be evident that if the moving force be a force communicated to the rack bar 45 tending to shift the same laterally or transversely of, the machine, such force can be effective to cause translation of the translatory table up to an angle of the cam channel 30 with respect to the longitudinal axis of the machine, which angle is determined by the friction'to'beovercome in various moving parts, and also by the co-eflicient of friction of the cam follower with its cam channels 30 and 43, respectively. For many conditions it will be found satisfactory to depend wholly on the force of lateral movement of such cam follower delivered thereto through the rack teeth, but in other cases it may be found desirable tosubject the translatory table toa force of direct translation parallel to the length of the table, as well as to the effect of the engagement of the cam follower with its respective cam channels.

The transl atory table 38 is provided with a longitudinally extending bore 49 wherein is journalled a, shaft which may be rotated to effect rotation of the tool carrying chuck. Such rotation then'serves torotate the tool being ground; but it is also necessary to at the same time effect motion of translation of the tool so that the grinding action will correctly follow the spiral of the flutes of the tool. Both of these movements (rotation and translation) of the tool areeffected from the single movement of rotation (or translation) to which the tool is effected by corresponding movement of the control element.

The shaft just referred to is shown as the rod 50, the front end of which carries the block 5|, said block being normally free to rotate on the shaft, but by tightening the set screw 52 said block may be locked to said shaft. A retainer plate 53 held to the front end of the rod 50 by the screw 54 serves to prevent this block from being unintentionally slipped off from the rod when the set screw 52 is loosened. The block 5| is provided with an enlargement 55 at one position, which enlargement is slotted to receive the end of the crank .arm 56 with a nice fit. This crank arm is held in place in said slot by means of the screw 51, which when loosened permits the crank arm to be rocked slightly on said screw as a pivot but which screw when tightened serves to clamp the crank arm securely to the enlargement 55 and thus retain said crank in fixed position with respect to the block 5|; the elasticity of the metal in which the slot is out being suflicient to allow such clamping of the crank arm to be effected merely by tightening the screw 51. Said crank arm carries at its free end the crank handle 58, the detailed construction of which is shown in section in Figure 16. This will be alluded to hereinafter.

Manifestly the foregoing scheme makes it possible to rock the shaft 50 through am desired angle merely by turning the crank handle 58, or said shaft may thus be rotated through several revolutions as required to effect grinding of the entire length of the flute of the tool.

At the rear portion of the bore 49 said bore journals the tubular shaft section 59; and the rear end of said tubular shaft section is enlarged to provide the chuck head 60. This chuck head is provided with the socket 6| to receive the end of'the tool to be ground, said tool being locked to the chuck head by the set screw 62. The tool itself is shown at B3, and a typical form of such tool which may be ground by this machine is shown in Figure 13. Said tool is shown as havin the several spiral flutes 64, each of which has the cutting edge 65; and it is a prime purpose of the machine of the present invention to provide for accurately grinding each of these cutting edges, accurately following the spiral of the flute, and also making provision for the number of flutes and cutting edges with which the tool is provided, in the case of the illustrated tool, four.

The shaft rod 59 is drivingly connected to the shaft tube section 59 by providing a drive fit between t ese two parts, the. end of the. rod bein forced in o the bore of the tube. This scheme s. her inshown e d, hoszheen ad ed vfor o hveh ehee in assemb ing the devi e. Manifestly other arrangements mi ht. be subst tutedthe efor desir d.- Eurth rmore, I; ha e n Fi u e shown e Washers or skets. 64 andBSfi h Wash r 64 e n on hetu ular section .9. and se n ro e t a inst ent y of dust. and the like into the interior of the here 49 at points adjacent to, the r ndi g pos t on- Ihe Wash thi on. the. t bu ar s tion-fiteee l o he d seiibed, omipe orms e milar uncti n of p o,-. eetieh aga st-entr oi d st, ete i to th bore ociiateh o. he ront e d of th m hi e- Th t ula sectio 6t, ust refe red er i he ro hoi s otioh :0, workin wi h n the ront her ieh o he bo e The. re r end porti nhis tubu ar see i h 6.6 s Provi d w h. the inio teeth 6. wh th. h w the teeth of e o k 5. to th rotat on o seidubul s t on. 66 e e t h t. th t ol; n h ir ion or th other; lateialiy of the table, and thus serves, to ef e t ir -oi h hem ollow r n s resoett camohannels already despieibed.

"The? front end (if saidtuhii-lar section 6,6 has connected'to .itthe disk as by the screws 5,9. Said 3 th 68 i r e te i h a s tabl o e o fia'sstherod shaftis'ection 5.0; and in the arrange Iflpfit shown 'saidirod; shaft is pi qvided with the he et f th t ite th. t dish 68," sd'th'at' the hotefof said dish; is made la ge ehoiig hf to accommodate flange 10 as shown i h s flene 'se v i is. o k h rod: shaft section against endwise. movement with rspeotlto the tuhulai section 66; but freerotation bto 'zeenthse parts is permitteduntil provision isfmadeto p lot eat such free rotation." That pro- ViSi'onI havefrhade a s willjnow he e) gplair ied I The, crank" ar'ni' 581 15. provided with the spring retracted bin 61' stud I I which has its rea end normally .prbj ected! by the. spring 1 2'. into; the positip iiownjm; sevlgal of the figures, including Fi ures, 1, 2, send 1.6. sai studi s grqilidedwith the head T3. which may he readilyv g asped and l ed; t a l to, c pres e h ine, a t draw the end; 1 .4 of said stud iorwaijdly from the position sho'wn particularly ilfhFigilIIe 16, Then, when said head is released the spring. will again t heu in otheoo tien d. ?-T 1, 2, 3. and. fiyplcoi ot gft fully. so r jected said end 'L l 'of. theist u d.willengagepnepf the] hqlesl provided in. the" disk :68. for" reception o d t d end, im ooking e rthhehdxthhs also looking the 'head & l and therodshaft and the tool chuck to the said disk; and since said disk is connected to, the. tubular'section' 65 it follows that; the pinionis thus also looked to the 99 h c {is a nse u nce, under thesleconditi ns ttien of h thh t i lrv bPthftq. tate the: tool, arrying huck and. also he. inio 1 and. hh h e h n he a follower will be shifted laterally at the same-time a t to l e o 'e si b ta ion of he c k..

' It was re iou y ade ident at. lateral shifti gof the cans follower block will'serve to cause the translation tahleto shift longitudinally f. e haehme theti s. aralle o he. x soi he F 9 Qtrfi d. b h chu k: The e ore o a e the r hk. thsil herforrh imul aneous y Pth he tion q hei eio shoo s nd ts o l hdtho t es o eh i 'so e e tsw t l reh l r tor'y ent htl heoi he oolt hese omi l d movements. will. pr d c a spi al la between the tool and. the point of contact. of the 2&23390 rinding wheel withthe tqolsurface; as willpre'sehtly be made moreapparent.

Now the. ratehftranslajtion' of the translatory tabl in comparisonto the rate of rotation will depenolon the angle. atwhich the cam'channel lies. with respectto the transverse plane ofzthe machine and. by: adjusting hat an e. yturn t wh l. 3t 'tofthe. proper an ular position it is possible to. estahlisheany desired pitch angle'and pitoh eh th in this oombinedmovement. Hav i ohee s tsor justed the wheel position and haying n loo ed the crank to the. disk 8, back nd: orth rota io s mparted to the crank by the operator w l ser e to fi t. spiral movements of he t l ehd'by ious y a justin the. whee to the co ect angl such spi l movements may hema i e to orr pond; exactly o he spirals of he u s. o he oo s 'Ehusit. is. possible to. brin theoherot ohe o themae ine. to exac re str with he'r uitemehts of the flu esalready exist.- he h. the tool ts ;v and t nsur thatthemovem e shhoa ed Q- he t ol l e corr ct for onti s he-un orm hs semeht i'the ind.- ing wheel with said flutes and their cutting-edges;

She; egoihs exp ahe o sho howthe detzee Qt Kate of eh t l mo ment. impa ted to e too moymade. to o r sp d to; the de ee e o pir lual e i in n. t e flutes. of he-to l: W 21 ev denthat in o der o e e t ottttt ti tiihe Q 'theoht h d es o said. flutes thetool, ehi eot hi, hetehe ket a sobe b ou h to the; tor t thsh' er oos t o f any'eiv ee zwise position of the too]; to ensure; that such spirolliesmevem h t; he o wi l: not. on oreso h i-t he pi oi the o flutes bot/a s hetteht i b esta lished and i l; ntinue he Wt ht e in-tithe- Wheel-and the cutt n ed tt ofihteshzE e te ih t show he r nd n Wheel in ts. os t on: r late o t e o l: self. Th et hd hsw eel how s. rsuit b eme r ai s th bot hdu hi or: he s able mate al; nd h Whee e. i i ener ly on ea fonmto tt ioht w h tst htr hi' fi; r ed; b he r e sha t o hown-)1; nd, ts d e 1 9 3 119 make e. f qt h h oo flute ee the rinding a. ion hete h;-. W thi h arteneement the, g qingiine wh e rotates h: axis --1 .ore. e1; to he ol.v @31 but den ly o her re at onsh s mi h b hbs tteciy de r Theooi ro me mediate interestthis; discussiqn; isthatsaid r nd n Wh e d akes; o h eet, i hthe oo flute-at t xe HQ i QQr pace- By o se in he. set S e mo rarily h ank ohdiloeh .1. ma edr; r teed Witheutef e he tation-5 he o i hu h Durihs h i e he i kafiswi ly e ur ed biz-t e tu h hef; he ranky hus ef ectin a; m ement i' te etieh;ehdwi epot hetoo h ck, riditool;

and; thus; the tool be brought; endwise into txtheeutti e, ed eofthe flute; hut-I ha e also madefi fi l ifihf adil einsthe m ine from timeto jtimelto bring thistrelationship into 9 effect for each of the flutes of a multi flute' tool successively, as I shall now show:

These cutting tools are currently made and in use with various numbers of flutes and cutting edges, but in all these cases said flutes are'equally spaced around the circumference of the tool itself. It is evident that if at any time the crank 58 be rotated through some angle while at the same time-leaving the disk 68 stationary, as by dis-engagement of the'stud end M from the hole of said disk, and if the said stud end be then re-engagedwith another hole of said .disk 68, a fresh relationship will be established wherein the tool has been set to a different angular position with respect to the grinding point of the grinding wheel; since the .non-rotationof the disk 68 during such re-setting has permitted the tubular shaft section Eli-to remain idle, and therefore there has been-no movement of table translation effected during such? rotation of the tool chuck andtool. 2T0 this end I have provided various holes combinationsin the disk'68so that'said stud end-14 may be engaged with selected ones thereof from time to time, corresponding to the numbers of flutes existing in the Various tools being ground from time to time." r L I Q -"I have, in the machineiiillustrated made provision for successiv'ely grinding'the flutes of tools having the following numbers of flutes, namely, 2, 3, 4', 5, 6,- 8, 10, 12,;20'a'ndt24J The 'flutesof such range of tools may be many case successively ground in very simple manner and with very simple re"-setting of thecrank and the stud end 14 'as I shall now show: r

Referring to Figure 4 there are shown the five circles 18,19, 80, 8| and 82, drawn around the axial center of the shaft rod 50 whereon the crank arm may be rotated. Each of these circles is the positioning of a plurality of holes into any one of which the stud end 14 maybe engaged when the crank'arm has been brought to the'properposition with respect to the block by loosening the set screw 51 and thereafter re-tightening said set screw. The holes .on each-of these circles are uniformly spaced, so that said holes will correspondto uniformly spaced flutes :of tools falling in thecategoryof such circle; :The circle'18 carries 24 holes (2 of which are hidden by the crank arm)"; the circle 19 carries 20 holes (20f which areh'idden by the crank arm) the circle 80 carries 4v holes; the circle 8| carries 3 holes (1 of which is hidden by the crank arm) and the circle 82 carries2 holes (liof which is hidden by the crank arm). By setting'the crank arm to such a' position that the 'stud' end 14 may engage with 110188 of the category of the circle 18 -(havingloosened the set screw'51'for this purpose, and having .then-re-set said set screw aftr'so re-settingthe crank arm) it follows that when the stud end 14 is disengaged from the disk. 68 saidcrank arm may be turned to bring the stud end successively into register with any of the holes'of the category of the circle. 18, and then by releasing the end of the crank arm'and allowing the spring I2 to function, the stud end 14 will engage withand lock the crank arm tosuchhole and thus to the diskatthe angular position dictated by such hole. Thus,'if we are grinding a tool having 24 flutes we may, "upon" completingthe grinding .of a given flute, merely draw out the'studend from the hole, turn the crank itself a slight amount to register with another hole, and allow the stud end 14 toengage with such other hole,-whereupon correct relationship willjbe established for grinding'the next flute of suchseries of' 24 flutes; and

flute, successively grinding'all the flutes of the tool.

If, then we have in hand a tool having some other number of flutes, we may, if need be, loosen the set screw 51, rock the crank arm to bring the stud end 14 into registry with the proper circle, and then re-lock said set screw. 'Thereupon the operations may be performed for a tool of'the number of flutes which may be accommodated by the category of such new circle. In this connection it is to be noted that the circle 18, having 24 holes, may be used for tools having either 6, 8, 12 or 24 flutes (skipping the proper holes when grinding tools of less than'24'fiutes); the circle 19, having 20 holes, may be used for tools having either 5, 10 or 20 flutes (skipping the proper holes when grinding tools of less than 20 flutes); and the circles 80, Bland 82, having 4, 3 and 2 holes, respectively, may be used forgr'inding tools of said numbers of'flutes. Althoughthere are certain numbers of flutes wherein holes of more than one circle may beused (as'for example','2 fluted tools, still the foregoing distr'ibution'of work is suggested as desirable. 1

Conveniently the holes are all designated by the numerals 83 for convenience. Examination ofFigure 4 shows that in placing. the holes in cause both these movements must be generated and transmitted to the said chuck. I have also pointed out that by merely turning the turntable the ratio between rate of translation (endwise of the shaft) and angular velocity may be made anything from zero to infinity; 'or, considering'the inverse of said ratio, said inverse may be made anything from infinity to Zero. It is therefore evident that if We merely subject the machine to the rotary force delivered to the crank, without also subjecting it to a translatory force, we shall be able to produce the desired rotary movements of the chuck and tool, as long as we do not set the calibration wheel 3| to such angles as would produce too fast a translatory movement. In other words, as long as the flutes are not excessively steep. In the grinding of fluted cutting edges of most tools the foregoing condition will apply, since in most cases'the steepnessofzthe flutes will be found not excessive, and both the movements can be effected merely by subjecting the crank to rotary movement. 3 I Itis, however, tobe noted'that when manipulating the crank 58 it is also possible to exert a pulling or pushingforce on the same, so that the movements of endwise translation maybe assisted in this manner, and tools having very steep flutes can thus be handled.

Sometimes it may be found desirable tomake provision for exerting'endwise force on the translation table independently of manipulation of the crank; In this connection it is noted that such endwise force can effect both of the movements of translation and rotation as long as the steepness of the flutes is not too small, since we now have the inverse condition from that previously considered. I have, therefore, shown in Figures 2, 3 and 4 the bracket 84 secured to the stand by suitable screws, said bracket having the laterally extending arm 85 with the upstanding pin or stud '85. The translatory table is provided with the upstanding pin or stud 81, so that a lever arm such as shown by the broken lines 88 (see Figure 1) may be engaged with both said studs 86 and 81 to effect back and forth or translatory movement of 'the table merely by swinging said lever arm back and forth.

Although the wheel 29 is shown as provided with the degree markings 33 ,(see Figures 2 and 3), still it is evident that other suitable markings might be substituted, as for example such markings as would directly indicate flute pitches, or other markings corresponding to the termsused in the machine tool art.

Evidently when a lever armsuch as shown at 8B is used to effect back and forth Or translatory movements of the translatory table suitable pin and slot connections should be provided between said lever and the studs 86 and :81 or other provision should be madefor the angularity which will occur in rocking of the lever.

Examination of Figure 12 shows that the end portions of the tubular shafts 59 and 66. are of larger diameter than those. portions of these shafts which lie in the central'portion of the-bore 49,said bore providing shoulders adjacent :to the end portions, and against which the enlarged portions of the tubular shafts bear. A'nyendwise movement of. the shaft. members is thus prevented, so that the translation of the tool chuck and the tool is properly controlled. The shoulders aforesaid are shown at 8:3 and 99 in Figure It is also evident that. movement or the table endwise of the shaft should be limited to. such amount. as will properly grind the tool, flutes,; but further movement towards the free end of the tool isunnecessary; and movement in the opposite. direction (towards; thechuck end of the tool) should be positively limited so, that the grinding action. will not inadvertently be carried beyond thecutting edges of the flutes. and ontothe chuck portion of" the tool. In Figure I Ihaveishown a simple means to "effect such. limitations. of movement-of the translation table. I havethere shown the bracket. extension lll'carried by'thebase portion. of. the, stand; and: having. the upstanding arms 92and93, The rear-end of the-translation table carriesthe platefid: which isishown as pro.-

vided: with the laterally extending arm 95;which 7 travels betweensthe arms; 92 and 93; and? set screws. '96: and 9-! threaded through said arms 92 and 93 serve to limit-themovements of the arm 95"; and thus also limit the translatory movement of the table at: such pointsas are determined by the. setting of saidset screws.-

It will also be noted" that the relation between the movements of rotation and translation depends, on the" relative interaction of thev cam channels:30i'andt43, with both offwhich the cam follower is: engaged. When these'cam channels are straight as-shownin. Figures 6 and'9, in particular, the ratio oferotaryandztranslatory movements willbenconst-ant, corresponding to spirals of-1 uniform pitch throughout the translatory movement.- It-is, however, evident that by specially-forming one or both of said channelcams it ispossible to securea spiral movementof nonuniform character, witheither an increase or a decrease of pitch of the flutes as measured from one-endof: the tool tothe other end-thereof: I

therefore contemplate the use-of cam channels of I I claim:

1. In a grinding -machine, :for rotary cutting tools having flutes located at regularly spaced positions around such tool, the combination of a translatory table, means to support said table for direct straight line translation of the table, a tool holding chuck journalled-in one end portion of the table for rotation on an'axislparallel to the directionof table translation; a tubular shaft element journalled in the other end portion of the table for rotationabout an axis co-axial with the axis of the chuck; said tubular shaft having inner and o'uter ends, a pinion in connection with the inner end portion of the tubular shaft, a rack element 'in'meshing engagement with said pinion, therebeing a trackway in the table for said rack element'extending in a direction: non-parallel to the rotational axis of the'tool holding chuck and the tubular shaft, a turntable journalled in the supporting means adjacent to the translatory tablefor angular adjustment about an axissubstantiallyintersecting thexaxis of rotation ofthe tool holding chuckv and. the tubular shaft; a track way in the turntable, a turntable slide working in said trackway, a companion. trackway inthe rack element, a rack element slide working in the rack elementtrackway, a pivotal connection between theturntableslide and the rack-element slide, whereby movements of translation of the translatorytable'and movements or rotation of the tubular shaft are conj'ointly' effected in proportion dependant oni the. angularadjustment of the turntable, the toot. holding chuck including a shaft extension extending: through the tubular shaft to a positi'on adjacent to the outerend of the tubular shaft away from. the pinion, an: indexin-g' diskisecuredj to the outer end: of one: of the shaft elements, said indexingsdiski being provided with a-i'series'of uniformly angularly'spaced indexing holes,. an indexing crank secured to the outer end of the other shaft element, and apin elementinconnection: with the cranhelem'ent and engageable with a selected-Jone of'said series of indexing holes; whereby said: crank may be manipulated by an operator to exert both rotational; andf translatory" forces on the crankrto thereby subject the shaft; elements tovrotational forces and to translatoryrorces simult'aneouslyto therebyeffectzcombinedfmovementsof rotation of the/shaft. elements andrcorresponding translatory movements or: the shaft elements" andi the. table eiementrorau angular position'srof'adjustment of the turntable; the: tool holding chuckbeing locatedi at: that emit of the device opposite to the position: or the indexin rdisk; and the? indexing crank, whereby rotational movements of the crank: are effected I without: interference trom' the tool; holdingwchuck' and a; tool carried thereby; substantiallyas described? 2; mdevice'xasdefihed in claim: 1, whereinthe indexing; disk. is secured tothe outer: end: of the tubular? shaft. and the indexing crank is: secured to theilouterlend ot"! the tool holding chuck shaft extension; substantiallyas" described:

' 3; A-. device: as defined'zin' claim: 1-, wherein the indexing' diskfis .pr'ovide drwithl a: plurality offse'riies oftuniformly angularlyrspaced iride'xingihol'es; and wherein: the: indexing crank: engageable with theholesiof anyroneionsaidiseries as-select'e'd, sub" stantially as;describedi' V V 42. Ardevicefi as defined in? claim 1; wherein the indexing dislii-is. secured." to the outer end of the tubular shaft and the indexing crank is secured to: the outer: end Of tHGtt'OOI holding 'chuck shaft extension,- and wherein Y the indexing'dis'k 'is-pro-= 13 vided with a plurality of series of uniformly angularly spaced indexing holes, and wherein the indexing crank is engageable with the holes of any one of said series as selected, substantially as described.

JOHN V. NELSON.

REFERENCES CITED Number file of this patent:

14 UNITED STATES PATENTS Name Date Penney Aug. 3, 1880 Garlent Apr. 24, 1928 Judge Mar. 3, 1936 Chittenden Aug. 27, 1940 Umbdenstock May 1, 1945 FOREIGN PATENTS Country Date Switzerland Aug. 9, 1911 Germany Mar. 1, 1926 

